Randomized Controlled Trial of Tirzepatide for Methamphetamine Use Disorder

This is a phase 2, randomized, double-blind, placebo-controlled, parallel-group trial evaluating the tolerability, safety, and preliminary efficacy of tirzepatide for the treatment of individuals with moderate or severe methamphetamine use disorder (MtUD). The central hypothesis of the proposed research is that tirzepatide is a safe and potentially efficacious treatment of MtUD. Participants will undergo study procedures over 32 weeks, including: 1. completing self-assessments 2. undergo brief physical and review of medical and psychiatric history 3. provide urine and blood samples 4. medical management sessions 5. weekly subcutaneous study medication injections

Inclusion Criteria: * be aged 18 to 65 years; * have moderate or severe methamphetamine use disorder; * have active pattern of methamphetamine use; * be interested in reducing or stopping methamphetamine use; * be able and willing to provide informed consent, comply with all study procedures, and adhere to weekly study medication injections; * be overweight or obese (body mass index ≥25 kg/m²); and * (only for biological females) agree to use acceptable contraception and undergo urine pregnancy testing unless unable to become pregnant Exclusion Criteria: * report using any glucagon like peptide 1 receptor agonists (GLP-1RA, including tirzepatide), sulfonylureas, or insulin in the past 90 days; * have a current eating disorder or severe alcohol or substance use disorder; * have personal or family history of medullary thyroid carcinoma, history of multiple endocrine neoplasia type 2, or hypersensitivity, angioedema, or anaphylaxis to GLP-1RAs or tirzepatide; * have Stage 3 or higher chronic kidney disease, inadequately controlled diabetes, history of diabetic retinopathy, any unstable or serious medical or psychiatric condition, or any other reason or clinical condition that may either interfere with study participation or make the study participation unsafe (per investigator judgement); * are currently pregnant, breastfeeding, or planning pregnancy; * have received an investigational drug within 30 days of informed consent; * require psychiatric hospitalization; * have recent suicidal or current homicidal ideation; * are incarcerated or in court-mandated residential placement; * have unsafe use of alcohol, benzodiazepines, sedative/hypnotics, or other substances; or * have use of concurrent medications that may pose safety risks or interfere with study procedures.